<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
<meta http-equiv="content-type" content="text/html; charset=ISO-8859-1" />
<title>JSONServiceInvoker xref</title>
<link type="text/css" rel="stylesheet" href="../../../../../stylesheet.css" />
</head>
<body>
<div id="overview"><a href="../../../../../../apidocs/com/totsp/gwittir/client/jsni/JSONServiceInvoker.html">View Javadoc</a></div><pre>

<a name="1" href="#1">1</a>   <em class="jxr_comment">/*</em>
<a name="2" href="#2">2</a>   <em class="jxr_comment"> * JSONServiceInvoker.java</em>
<a name="3" href="#3">3</a>   <em class="jxr_comment"> *</em>
<a name="4" href="#4">4</a>   <em class="jxr_comment"> * Created on November 9, 2007, 8:43 PM</em>
<a name="5" href="#5">5</a>   <em class="jxr_comment"> *</em>
<a name="6" href="#6">6</a>   <em class="jxr_comment"> * To change this template, choose Tools | Template Manager</em>
<a name="7" href="#7">7</a>   <em class="jxr_comment"> * and open the template in the editor.</em>
<a name="8" href="#8">8</a>   <em class="jxr_comment"> */</em>
<a name="9" href="#9">9</a>   
<a name="10" href="#10">10</a>  <strong class="jxr_keyword">package</strong> com.totsp.gwittir.client.jsni;
<a name="11" href="#11">11</a>  
<a name="12" href="#12">12</a>  <strong class="jxr_keyword">import</strong> com.google.gwt.core.client.JavaScriptObject;
<a name="13" href="#13">13</a>  <strong class="jxr_keyword">import</strong> com.google.gwt.user.client.DOM;
<a name="14" href="#14">14</a>  <strong class="jxr_keyword">import</strong> com.google.gwt.user.client.Element;
<a name="15" href="#15">15</a>  <strong class="jxr_keyword">import</strong> com.google.gwt.user.client.ui.RootPanel;
<a name="16" href="#16">16</a>  
<a name="17" href="#17">17</a>  <em class="jxr_javadoccomment">/**</em>
<a name="18" href="#18">18</a>  <em class="jxr_javadoccomment"> * The JSON service invoker is a utility class for invoking JSON-P style web </em>
<a name="19" href="#19">19</a>  <em class="jxr_javadoccomment"> * services. </em>
<a name="20" href="#20">20</a>  <em class="jxr_javadoccomment"> * </em>
<a name="21" href="#21">21</a>  <em class="jxr_javadoccomment"> * It has a single method to invoke a service with a specified callback method.</em>
<a name="22" href="#22">22</a>  <em class="jxr_javadoccomment"> * @author rcooper</em>
<a name="23" href="#23">23</a>  <em class="jxr_javadoccomment"> */</em>
<a name="24" href="#24">24</a>  <strong class="jxr_keyword">public</strong> <strong class="jxr_keyword">class</strong> <a href="../../../../../com/totsp/gwittir/client/jsni/JSONServiceInvoker.html">JSONServiceInvoker</a> {
<a name="25" href="#25">25</a>      
<a name="26" href="#26">26</a>      <em class="jxr_javadoccomment">/**</em>
<a name="27" href="#27">27</a>  <em class="jxr_javadoccomment">     * Invokes a JSON-P service. </em>
<a name="28" href="#28">28</a>  <em class="jxr_javadoccomment">     * </em>
<a name="29" href="#29">29</a>  <em class="jxr_javadoccomment">     * &lt;b&gt;Note&lt;/b&gt;: If you make multiple calls to a service with a single</em>
<a name="30" href="#30">30</a>  <em class="jxr_javadoccomment">     * callback method name, calls made AFTER the first one will effectively be lost,</em>
<a name="31" href="#31">31</a>  <em class="jxr_javadoccomment">     * or you will get multiple resonses sent to the later callback listener.</em>
<a name="32" href="#32">32</a>  <em class="jxr_javadoccomment">     * </em>
<a name="33" href="#33">33</a>  <em class="jxr_javadoccomment">     * For JSON-P services like the Facebook API, where you can specify different</em>
<a name="34" href="#34">34</a>  <em class="jxr_javadoccomment">     * different callback method names for each call, you should avail yourself of this.</em>
<a name="35" href="#35">35</a>  <em class="jxr_javadoccomment">     * For services like the Flickr Feed service, you should simply be aware of this.</em>
<a name="36" href="#36">36</a>  <em class="jxr_javadoccomment">     * @param url URL to invoke. This will become the "src" attribute of a &amp;lt;script&amp;gt; tag on </em>
<a name="37" href="#37">37</a>  <em class="jxr_javadoccomment">     * the page.</em>
<a name="38" href="#38">38</a>  <em class="jxr_javadoccomment">     * </em>
<a name="39" href="#39">39</a>  <em class="jxr_javadoccomment">     * @param callbackMethodName The name of the callback method the service will invoke. This will be added to </em>
<a name="40" href="#40">40</a>  <em class="jxr_javadoccomment">     * the window/$wnd reference.</em>
<a name="41" href="#41">41</a>  <em class="jxr_javadoccomment">     * @param callback A callback that will be invoked by the service.</em>
<a name="42" href="#42">42</a>  <em class="jxr_javadoccomment">     */</em>
<a name="43" href="#43">43</a>      <strong class="jxr_keyword">public</strong> <strong class="jxr_keyword">static</strong> <strong class="jxr_keyword">void</strong> invoke( String url, String callbackMethodName, JSONCallback callback) {
<a name="44" href="#44">44</a>          createCallbackMethod( callbackMethodName, callback );
<a name="45" href="#45">45</a>          createScriptTag( url );
<a name="46" href="#46">46</a>      }
<a name="47" href="#47">47</a>      
<a name="48" href="#48">48</a>      <strong class="jxr_keyword">native</strong> <strong class="jxr_keyword">static</strong> <strong class="jxr_keyword">void</strong> createCallbackMethod( String callbackMethodName, JSONCallback callback  )
<a name="49" href="#49">49</a>      <em class="jxr_comment">/*<em class="jxr_comment">-{</em></em>
<a name="50" href="#50">50</a>  <em class="jxr_comment">        $wnd[callbackMethodName] = function( argument ){</em>
<a name="51" href="#51">51</a>  <em class="jxr_comment">            var wrapped = @com.totsp.gwittir.client.jsni.JSONServiceInvoker::wrapObject(Lcom/google/gwt/core/client/JavaScriptObject;)(argument);</em>
<a name="52" href="#52">52</a>  <em class="jxr_comment">            callback.@com.totsp.gwittir.client.jsni.JSONCallback::onJSONResult(Lcom/totsp/gwittir/client/jsni/JavaScriptObjectDecorator;)(wrapped);</em>
<a name="53" href="#53">53</a>  <em class="jxr_comment">        }</em>
<a name="54" href="#54">54</a>  <em class="jxr_comment">    }-*/</em>;
<a name="55" href="#55">55</a>      
<a name="56" href="#56">56</a>      <strong class="jxr_keyword">static</strong> <a href="../../../../../com/totsp/gwittir/client/jsni/JavaScriptObjectDecorator.html">JavaScriptObjectDecorator</a> wrapObject( JavaScriptObject object ){
<a name="57" href="#57">57</a>          <strong class="jxr_keyword">return</strong> <strong class="jxr_keyword">new</strong> <a href="../../../../../com/totsp/gwittir/client/jsni/JavaScriptObjectDecorator.html">JavaScriptObjectDecorator</a>(object);
<a name="58" href="#58">58</a>      }
<a name="59" href="#59">59</a>  
<a name="60" href="#60">60</a>      <strong class="jxr_keyword">static</strong> <strong class="jxr_keyword">void</strong> createScriptTag( String url ){
<a name="61" href="#61">61</a>          Element script = DOM.createElement(<span class="jxr_string">"script"</span>);
<a name="62" href="#62">62</a>          DOM.setElementAttribute( script, <span class="jxr_string">"src"</span>, url );
<a name="63" href="#63">63</a>          DOM.setElementAttribute(script, <span class="jxr_string">"type"</span>, <span class="jxr_string">"text/javascript"</span>);
<a name="64" href="#64">64</a>          DOM.appendChild( RootPanel.get().getElement(), script );
<a name="65" href="#65">65</a>      }
<a name="66" href="#66">66</a>      
<a name="67" href="#67">67</a>  }
</pre>
<hr/><div id="footer">This page was automatically generated by <a href="http://maven.apache.org/">Maven</a></div></body>
</html>

